US4892702A - Light-water nuclear reactor vessel and process for its manufacture - Google Patents

Light-water nuclear reactor vessel and process for its manufacture Download PDF

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Publication number
US4892702A
US4892702A US07/258,358 US25835888A US4892702A US 4892702 A US4892702 A US 4892702A US 25835888 A US25835888 A US 25835888A US 4892702 A US4892702 A US 4892702A
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United States
Prior art keywords
vessel
max
welding
nuclear reactor
unit components
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Expired - Lifetime
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US07/258,358
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English (en)
Inventor
Alain Vignes
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Areva NP SAS
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Framatome SA
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Assigned to FRAMATOME, TOUR FIAT reassignment FRAMATOME, TOUR FIAT ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: VIGNES, ALAIN
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C13/00—Pressure vessels; Containment vessels; Containment in general
    • G21C13/08—Vessels characterised by the material; Selection of materials for pressure vessels
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C13/00—Pressure vessels; Containment vessels; Containment in general
    • G21C13/08—Vessels characterised by the material; Selection of materials for pressure vessels
    • G21C13/087—Metallic vessels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K15/00—Electron-beam welding or cutting
    • B23K15/0046—Welding
    • B23K15/0093—Welding characterised by the properties of the materials to be welded
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K15/00—Electron-beam welding or cutting
    • B23K15/04—Electron-beam welding or cutting for welding annular seams
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Definitions

  • the invention relates to a process for the manufacture of a light-water nuclear reactor vessel comprising a shell of great thickness, e.g., greater than 100 mm.
  • the invention relates to a process for the manufacture of a pressurized-water nuclear reactor vessel and to a vessel of this kind.
  • Pressurized-water nuclear reactor vessels consist of a shell of overall cylindrical shape, closed at its ends by dished bottoms.
  • the vessel containing the core is exposed to intense neutron radiation and needs to withstand the temperature and the pressure of the primary fluid, consisting of water at a temperature in the region of 320° C. and at a pressure of the order of 150 ⁇ 10 5 Pa.
  • the vessels of pressurized-water nuclear reactors which are at present in use have a thickness which is generally between 200 and 300 mm and must to be constructed from cylindrical shells and from a first dished bottom, these components being assembled by welding.
  • the second dished bottom of the vessel forms the closure head which is fastened by means of studs when the vessel is commissioned, onto a flange which is welded onto one of the shells forming the vessel.
  • the assembly of the vessel is carried out by submerged arc welding with filler metal, and this operation requires the ends of the components to be assembled to be suitably machined in order to delimit two welding chamfers which are then filled with filler metal.
  • the weld thus produced must then be remachined on the inside and outside and subjected to a heat treatment.
  • the filler metal introduces a certain discontinuity into the metallurgical structure of the vessel metal, and this may be awkward, especially if a welded joint is situated in a region of the vessel opposite the core.
  • the assembly of a nuclear reactor vessel is therefore a very lengthy operation, which requires the use of complex means and the presence of highly qualified personnel.
  • the execution of the filling of the weld chamfers requires many welding passes and the metal which is deposited must to be monitored in order to prevent the presence of any foreign particle in the welded joint (slag inclusions, etc.).
  • the object of the invention is therefore to provide a process for the manufacture of a light-water nuclear reactor vessel comprising a shell of great thickness, e.g. greater than 100 mm, symmetrical in revolution, consisting in shaping at least two unit components of overall symmetrical shape in revolution and generally annular, and in then assembling them by welding over their entire thickness to produce the vessel, this process permitting the production of welded joints of very high quality and the manufacture of components possessing very good radiation resistance, with a time of execution which is much shorter than in the prior art.
  • the unit components whose wall thickness is greater than 100 mm, are made of a steel containing 2 to 2.5% of chromium, 0.9 to 1.1% of molybdenum and less than 0.15% of carbon, and the assembly of the unit components is carried out by welding by means of an electron beam, in a single pass, without filler metal, over the entire thickness of the components.
  • FIG. 1 is a view in axial section of a vessel of a pressurized-water nuclear reactor.
  • FIGS. 2, 3 and 4 are exploded views showing the various unit components forming a vessel and the way they are assembled.
  • FIGS. 5 and 6 are elevation views, in two perpendicular directions, of a plant for welding a nuclear reactor vessel by means of an electron beam.
  • FIG. 7 is a plan view of the plant shown in FIGS. 5 and 6.
  • FIG. 1 shows a vessel 1, comprising a middle section of cylindrical shape, together with a dished bottom 2 and a closure head 3 of hemispherical shape.
  • the closure head 3 is fastened onto the body of the vessel 1 by means of studs 4.
  • the cylindrical section of the vessel consists of two core shells 6 and 7, a pipe-carrying shell 8 and a flange 9.
  • the pipes 10 permit the vessel to be connected to the piping of the primary circuit.
  • the bottom 2 and the closure head 3 consist of two parts 2a, 2b and 3a, 3b, respectively.
  • the unit components 2a, 2b, 6, 7, 8, 9 and 10 forming the vessel body are assembled together by welding at the joints 11.
  • the parts 3 and 3b of the closure head are assembled by welding.
  • the region 12 in which the fuel assemblies forming the core of the reactor are arranged inside the vessel 1 is shown.
  • weld joints 11 between the two core shells 6 and 7, on the one hand, and between the upper core shell 7 and the pipe-carrying shell 8, which are level with the core, are those most stressed by the irradiation.
  • FIG. 2 shows the various unit components forming the reactor vessel, before they are assembled. Most of these components form shells or flanges of annular shape, with the exception of the two spherical end caps 2a and 3a.
  • edges delimit one or two chamfers in which filler metal is deposited by successive passes of automatic submerged arc welding.
  • edges and a part of the filler metal are then machined and the welded joint is then finished by depositing successive layers which themselves consist of successive welding passes. Very many passes must be performed in order to produce a welded joint.
  • the core shells 6 and 7 are assembled end to end into the shape of a shell 13.
  • the bottom 2 is assembled and is then welded onto the assembly produced.
  • This first assembly 18 forms the lower subassembly of the vessel (FIG. 4).
  • the upper subassembly 19 consists of the pipe-carrying shell 8 onto which the pipes 10 have been fastened, and onto which the flange 9 has been assembled.
  • the two subassemblies 18 and 19 are then welded to each other. All of these welds are performed by means of automatic submerged arc welding.
  • the closure head 3 itself is produced by submerged arc welding of the components 3a and 3b.
  • the various components forming the vessel have thicknesses which are generally between 200 and 300 mm.
  • the forged components 2a, 2b, 6, 7, 8, 9, 10, 3a and 3b forming the vessel are made of a steel containing chiefly 2 to 2.50% of chromium and 0.9 to 1.10% of molybdenum and whose carbon content does not exceed 0.15%.
  • the steel contains 2.25% of chromium and 1% of molybdenum.
  • the steels which may be employed for implementing the process of manufacture according to the invention have a composition such as defined below: C: 0.11 to 0.15%, Mn: 0.30 to 0.60%, Si: 0.15 to 0.35%, Cr: 2 to 2.50%, Mo: 0.9 to 1.1%, Ni: max. 0.30, P: max. 0.005, S: max. 0.005, Cu: max. 0.05, V: max. 0.01, Al: max. 0.02, Co: max. 0.03, Sb: max. 0.001, As: max. 0.012.
  • the various shells and spherical caps forming the vessel according to the invention have a thickness of between 200 and 300 mm.
  • the components 2a, 2b, 6, 7, 8, 9, 10 and 3a, 3b are wrought and shaped by means of known foundry and forging processes of the prior art, for the manufacture of the vessel's unit components.
  • the final assembly of the vessel 20 (FIG. 4) is produced by end-to-end welding of the lower subassembly 18 and of the upper subassembly 19.
  • the various welds are produced in a single pass, by means of an electron beam on the ends, which are placed so that they coincide, of the components to be joined.
  • Electron beam welding makes it possible to obtain joints without filler metal, whose radiation resistance is identical with that of the base metal.
  • FIGS. 5, 6 and 7 show a plant which makes it possible to perform the electron beam welding of the unit components which make up a nuclear reactor vessel.
  • the plant consists of an enclosure 30 of great size from which the atmosphere can be evacuated by means of a pumping system capable of producing a hard vacuum of the order of 10 -5 mm of mercury.
  • an enclosure of parallelepipedal shape has been provided, whose internal dimensions are as follows: length: 8.50 m, width: 7.50 m and height: 12.50 m.
  • the volume of such an enclosure is 800 m 3 .
  • An electron gun 31 with a power rating of 200 kW is fastened onto a carriage 32 mounted so that it can move along the lengthwise direction of a beam 33, itself mounted so that it can move in the vertical direction on two vertical columns 34 extending substantially over the entire height of the enclosure 30. This provides the electron gun with a range of travel of the order of 6 m in the transverse direction and of the order of 9 m in the vertical direction.
  • the gun 31 is mounted so that it can move in rotation on the carriage 32, over a range of 90°, around an axis which is horizontal and in transverse direction relative to the enclosure and around a vertical axis.
  • the electron beam welding plant also comprises a carriage 36 on which there is mounted a rotary platform 37 with a diameter of the order of 5 m.
  • the carriage 36 is mounted so that it can move inside the enclosure 30, so as to be capable of travelling over a range of the order of 3.30 m, in the lengthwise direction of the enclosure 30.
  • a plant such as shown in FIGS. 5, 6 and 7 makes it possible to produce all the welds of a nuclear reactor vessel assembly.
  • the components to be assembled are fastened onto the platform 37 and the electron gun 31 is placed in a horizontal position at the desired height in order to produce the welded joint.
  • the components are made to rotate around the vertical axis of the rotary platform 37 and the welded joint is produced by an electron beam in a single pass, at a speed of between 10 and 40 cm/min, depending on the thickness of the joint to be welded.
  • the pipes 10 may also be fastened by welding by means of an electron beam to the pipe-carrying shell 8 by using the plant in FIGS. 5, 6 and 7.
  • This operation can be performed by a process characterized by a connecting surface between each of the pipes and the shell which is of frusto-conical shape.
  • the steel employed for producing the components has the essential advantage of relatively low radiation sensitivity.
  • the initial temperature of the ductile plateau of this chromium-molybdenum steel lies below -20° C. This temperature rises to a level in the region of 0° to 10° C. after forty years of irradiation under the operating conditions close to the core of a nuclear reactor. These conditions correspond to the maximum lifetime of a nuclear reactor vessel. Consequently, the components made according to the process of the invention of a chromium-molybdenum steel are not subject to a cleavage failure due to unstable crack propagation, which can appear only below the ductile plateau. Any risk of crack propagation capable of giving rise to a leakage in the vessel is also avoided.
  • the invention can be applied to the production of any vessel for a nuclear reactor.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Welding Or Cutting Using Electron Beams (AREA)
  • Butt Welding And Welding Of Specific Article (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Arc Welding In General (AREA)
  • Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
  • Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
  • Physical Water Treatments (AREA)
  • Heat Treatment Of Articles (AREA)
US07/258,358 1987-10-16 1988-10-17 Light-water nuclear reactor vessel and process for its manufacture Expired - Lifetime US4892702A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8714323A FR2622041B1 (fr) 1987-10-16 1987-10-16 Procede de fabrication d'une cuve d'un reacteur nucleaire a eau legere et cuve de reacteur nucleaire fabriquee par ce procede
FR8714323 1987-10-16

Publications (1)

Publication Number Publication Date
US4892702A true US4892702A (en) 1990-01-09

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Country Status (14)

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US (1) US4892702A (cs)
EP (1) EP0312426B1 (cs)
JP (1) JP2530362B2 (cs)
KR (1) KR970004418B1 (cs)
CN (1) CN1015948B (cs)
AT (1) ATE76219T1 (cs)
BR (1) BR8805333A (cs)
CA (1) CA1292329C (cs)
CS (1) CS277578B6 (cs)
DE (1) DE3871071D1 (cs)
ES (1) ES2031263T3 (cs)
FI (1) FI884694L (cs)
FR (1) FR2622041B1 (cs)
ZA (1) ZA887541B (cs)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5207977A (en) * 1991-08-16 1993-05-04 General Electric Company Reactor pressure vessel with forged nozzles
US5442667A (en) * 1993-03-15 1995-08-15 Siemens Aktiengesellschaft Reactor pressure vessel with limited failure zones
US5721758A (en) * 1996-02-29 1998-02-24 General Electric Company Bottom head to shell junction assembly for a boiling water nuclear reactor
US6426986B1 (en) * 2000-08-23 2002-07-30 General Electric Company Forged nozzle shell course for a pressure vessel
AU2002218206B2 (en) * 2000-11-07 2006-01-12 Ecs Environment Care Systems Gmbh Device for catching flying insects
US20070189894A1 (en) * 2006-02-15 2007-08-16 Thamboo Samuel V Methods and apparatus for turbine engine rotors
US20120325940A1 (en) * 2011-06-27 2012-12-27 Alstom Technology Ltd Nozzle and nozzle assembly configured to minimize combined thermal and pressure stress during transients
CN107110559A (zh) * 2014-10-28 2017-08-29 超高温热水私人有限公司 热水储存装置
RU2633408C1 (ru) * 2016-12-28 2017-10-12 Акционерное общество "Научно-производственное объединение "Центральный научно-исследовательский институт технологии машиностроения", АО "НПО "ЦНИИТМАШ" Теплостойкая и радиационно-стойкая сталь

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101169984B (zh) * 2007-11-29 2011-01-26 贵州航天新力铸锻有限责任公司 百万千瓦级核电压力容器安全端制造工艺

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3456831A (en) * 1957-08-16 1969-07-22 Avesta Jernverks Ab Austenitic stainless steel pressure vessels
DE2537115A1 (de) * 1974-08-21 1976-03-11 Hitachi Ltd Verfahren zum elektronenstrahlschweissen
US4057163A (en) * 1975-07-08 1977-11-08 Cockerill-Ougree-Providence Et Esperance-Longdoz En Abrege "Cockerill" Metal container with thick walls
FR2390236A1 (fr) * 1977-05-11 1978-12-08 Steigerwald Strahltech Procede et dispositif de soudage par bombardement d'electrons
US4576785A (en) * 1983-06-14 1986-03-18 Carolina Power And Light Company Reduction in rate of radiation exposure to excore nuclear reactor components

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56109180A (en) * 1980-01-31 1981-08-29 Hitachi Zosen Corp Production of nozzle
JPS56119680A (en) * 1980-02-26 1981-09-19 Babcock Hitachi Kk Electron beam welding method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3456831A (en) * 1957-08-16 1969-07-22 Avesta Jernverks Ab Austenitic stainless steel pressure vessels
DE2537115A1 (de) * 1974-08-21 1976-03-11 Hitachi Ltd Verfahren zum elektronenstrahlschweissen
US4057163A (en) * 1975-07-08 1977-11-08 Cockerill-Ougree-Providence Et Esperance-Longdoz En Abrege "Cockerill" Metal container with thick walls
FR2390236A1 (fr) * 1977-05-11 1978-12-08 Steigerwald Strahltech Procede et dispositif de soudage par bombardement d'electrons
US4160150A (en) * 1977-05-11 1979-07-03 Steigerwald Strahltechnik Gmbh Method and apparatus for energy beam welding
US4576785A (en) * 1983-06-14 1986-03-18 Carolina Power And Light Company Reduction in rate of radiation exposure to excore nuclear reactor components

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
"Development of PWR Pressure Vessel Steels", Druce et al., Nucl. Energy, vol. 19, 10/80, pp. 347-360.
Development of PWR Pressure Vessel Steels , Druce et al., Nucl. Energy, vol. 19, 10/80, pp. 347 360. *
Nuclear Engineering, vol. 12, No. 133, 6/67, pp. 444 448, Reactor Pressure Vessels Design Fabrication Testing , Porse. *
Nuclear Engineering, vol. 12, No. 133, 6/67, pp. 444-448, "Reactor Pressure Vessels Design-Fabrication-Testing", Porse.
Technica, vol. 26, 1985, pp. 105 109, Behnisch. *
Technica, vol. 26, 1985, pp. 105-109, Behnisch.

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5207977A (en) * 1991-08-16 1993-05-04 General Electric Company Reactor pressure vessel with forged nozzles
US5442667A (en) * 1993-03-15 1995-08-15 Siemens Aktiengesellschaft Reactor pressure vessel with limited failure zones
US5721758A (en) * 1996-02-29 1998-02-24 General Electric Company Bottom head to shell junction assembly for a boiling water nuclear reactor
US6426986B1 (en) * 2000-08-23 2002-07-30 General Electric Company Forged nozzle shell course for a pressure vessel
AU2002218206B2 (en) * 2000-11-07 2006-01-12 Ecs Environment Care Systems Gmbh Device for catching flying insects
US20070189894A1 (en) * 2006-02-15 2007-08-16 Thamboo Samuel V Methods and apparatus for turbine engine rotors
US20120325940A1 (en) * 2011-06-27 2012-12-27 Alstom Technology Ltd Nozzle and nozzle assembly configured to minimize combined thermal and pressure stress during transients
US9695934B2 (en) * 2011-06-27 2017-07-04 General Electric Technology Gmbh Nozzle and nozzle assembly configured to minimize combined thermal and pressure stress during transients
CN107110559A (zh) * 2014-10-28 2017-08-29 超高温热水私人有限公司 热水储存装置
US10184687B2 (en) 2014-10-28 2019-01-22 Maxheat Hot Water Pty Ltd Hot water storage device
CN107110559B (zh) * 2014-10-28 2020-08-04 超高温热水私人有限公司 热水储存装置
RU2633408C1 (ru) * 2016-12-28 2017-10-12 Акционерное общество "Научно-производственное объединение "Центральный научно-исследовательский институт технологии машиностроения", АО "НПО "ЦНИИТМАШ" Теплостойкая и радиационно-стойкая сталь

Also Published As

Publication number Publication date
CA1292329C (fr) 1991-11-19
KR890007307A (ko) 1989-06-19
CN1015948B (zh) 1992-03-18
ATE76219T1 (de) 1992-05-15
EP0312426A1 (fr) 1989-04-19
CS277578B6 (en) 1993-03-17
KR970004418B1 (ko) 1997-03-27
ES2031263T3 (es) 1992-12-01
ZA887541B (en) 1989-07-26
CN1033334A (zh) 1989-06-07
DE3871071D1 (de) 1992-06-17
FI884694A7 (fi) 1989-04-17
FR2622041B1 (fr) 1990-03-09
FI884694A0 (fi) 1988-10-12
JPH021595A (ja) 1990-01-05
JP2530362B2 (ja) 1996-09-04
FR2622041A1 (fr) 1989-04-21
FI884694L (fi) 1989-04-17
EP0312426B1 (fr) 1992-05-13
BR8805333A (pt) 1989-05-30

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